Of course it's possible, even probable, that index fossils have been found near polystrate trees. Now different index fossils from vastly different parts of the geologic column, in situ, in polystrate tree layers -- that would be a major find. That's what you seemed to be implying you'd heard about but could not give evidence for.

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Could you tell me in plain language how these polystrate trees form -- passing vertically through multiple layers of sediment?


The sediment layers form relatively rapidly. And wood does not necessarily decay instantly:

Polystrate Fossil